The Internal Thermonuclear Experimental Reactor (ITER) is supposed to be the next crucial step on the way (iter) to commercial energy generation by nuclear fusion. It is more a political technological project than a scientific technological one. Born in the twilight years of the Soviet Union, it became caught up in detente politics between East and West. Its (scientific technical) goal is to show that energy generation by nuclear fusion is in principle possible. For this rather modest goal, after 70 years of effort, a giant collaboration spanning more than half the globe and three-quarters of the world’s gross national project has been set up. ITER’s construction is now in full swing in the south of France, and this chapter describes the tortuous route towards this endeavour, the gigantic costs involved and the sheer megalomania it entails.